Relay module

ABSTRACT

A relay module, by which a time required when a motor is optionally mounted on a machine tool or removed therefrom can be omitted. The relay module comprises only a case and terminal screws of an electromagnetic contactor for a motor from which internal components are removed. The relay module is disposed when the motor is not connected and an electromagnetic switch is disposed when the motor is connected. Further, the relay module or electromagnetic switch is wired at all times. When the motor is optionally mounted on the machine tool, it suffices only to replace the relay module thereof with the electromagnetic switch and no wiring job is additionally required. Further, when the motor is removed, it suffices only to replace the electromagnetic switch with the relay module and a job for removing the wiring is not necessary.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a relay module for relaying the wiringof a motor circuit, and more specifically, to a relay module used inplace of an electromagnetic switch used when an induction motor isconnected.

2. Description of the Related Art

When an induction motor is to be additionally connected to a machinetool, an electromagnetic switch must be mounted on the distributionpanel of the machine tool and the induction motor must be connected tothe machine tool through a wiring additionally connected to theelectromagnetic switch. Alternatively, as described below, when theelectromagnetic switch is mounted between two terminal bases previouslyprovided for the distribution panel, wirings are additionally connectedbetween the two terminal bases and the electromagnetic switch to connectthe induction motor. The connection of the induction motor will bedescribed with reference to FIG. 6.

FIGS. 6(A) and 6(B) are diagrams explaining the induction motorconnected by the above conventional method, wherein FIG. 6 (A) shows thestate that the induction motor is not connected and FIG. 6 (B) shows thestate that the induction motor is connected, respectively. In FIG. 6(A), a distribution panel 20 is connected to, for example, an I/Ocircuit of a programmable machine controller (PMC) of a numericallycontrolled machine tool. The distribution panel 20 has two rows ofterminal bases 21 and 22 spaced apart from each other. When an inductionmotor 30 is to be connected to the distribution panel 20, anelectromagnetic switch 100 must be disposed between the terminal bases21 and 22 to turn ON/OFF power supplied to the induction motor 30, asshown in FIG. 6 (B). Therefore, the respective terminals 21a, 21b, 21cof the terminal base 21 must be connected to the primary terminals 100a,100b, 100c of the electromagnetic switch 100 through additional wiresand the secondary terminals 100d, 100e, 100f of the electromagneticswitch 100 must be connected to the respective terminals 22a, 22b, 22cof the terminal base 22 through additional wires.

Nevertheless, since this induction motor 30 is optionally provided forthe machine tool, whether it is to be mounted or not is often alteredeven in the time from the placement of an order from a user to theshipment of the machine tool. Moreover, several tens of the inductionmotor 30 may be used in a single machine tool. Consequently, a problemarises in that a job for mounting or dismounting the induction motor 30is increased even during a time until a single machine tool is shippedand each time the motor is mounted or dismounted, a job must be carriedout to mount and wire the above electromagnetic switch 100 or dismountit and remove its wiring.

Note, since the electromagnetic switch 100 is expensive, when theinduction motor 30 is to be removed, the electromagnetic switch 100 andthe wiring thereof are removed accordingly and restored to the stateshown in FIG. 6 (A).

As described above, it is very time-consuming to ship a single machinetool. Further, when a user actually uses the machine tool shippedthereto, he may mount or dismount the induction motor 30, and in thiscase a similar job must be carried out and this job is time-consuming inthe same way.

SUMMARY OF THE INVENTION

Taking the above into consideration, an object of the present inventionis to provide a relay module by which a time required when a motor isoptionally mounted on a machine tool or removed therefrom can beomitted.

To solve the above problem, according to the present invention, there isprovided a relay module for relaying the wiring of a motor circuit,which comprises only a case and terminal screws of an electromagneticcontactor for a motor from which internal components are removed.

The relay module for relaying the wiring of the motor circuit comprisesonly the case and terminal screws of the electromagnetic contactor forthe motor from which the internal components are removed. The relaymodule is disposed when the motor is not connected and anelectromagnetic switch is disposed when the motor is connected. Further,the relay module or electromagnetic switch is wired at all times. Whenthe motor is optionally mounted on the machine tool, it suffices only toreplace the relay module with the electromagnetic switch and noadditional wiring job is required. Further, when the motor is removedfrom the machine tool, it suffices only to replace the electromagneticswitch with the relay module and the wiring need not be removed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an outside view of a relay module of the present invention;

FIG. 2 is a side view of the relay module of the present invention;

FIG. 3 is a cross sectional view of the relay module taken along theline X--X of FIG. 2;

FIG. 4 is a cross sectional view of the relay module taken along theline Y--Y of FIG. 2;

FIG. 5 is a diagram showing an arrangement of the relay module when itis mounted on a distribution panel; and

FIGS. 6 (A) and 6(B) are diagrams explaining an induction motorconnected by a conventional method, wherein FIG. 6(A) shows the statethat the induction motor is not connected and FIG. 6(B) shows the statethat the induction motor is connected, respectively.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described below withreference to the drawings.

An arrangement of a relay module of the present invention will bedescribed with reference to FIG. 1 through FIG. 4.

FIG. 1 is an outside view of the relay module of the present inventionand FIG. 2 is a side view thereof. In FIGS. 1 and 2, the relay module 1is composed of a case 10 and terminals (terminal screws) 1a, 1b, 1c, 1d,1e, 1f, 1h, 1i and 1j. The relay module 1 has an outside view similar tothat of an electromagnetic contactor (a type of an electromagneticswitch from which thermal relays are removed) provided to turn ON/OFFthe power supply of an induction motor. Note, as described below,although this relay module 1 is replaced with the electromagnetic switchwhen the induction motor is connected, at this time the terminals 1a,1b, 1c, 1d correspond to the primary terminals of the electromagneticswitch and the terminals 1f, 1g, 1h, 1i correspond to the secondaryterminals thereof. Further, the terminals 1e and 1j correspond to theterminals of the electromagnetic switch to which an operating voltage of24 V is applied.

FIG. 3 is a cross sectional view of the relay module 1 taken along theline X--X of FIG. 2. As shown in the FIG. 3, only the terminals 1athrough 1j are disposed to the back surface on the terminal side of thecase 10 of the relay module 1 and a contact portion 101 as a componentof the electromagnetic contactor is removed therefrom.

FIG. 4 is a cross sectional view of the relay module 1 taken along theline Y--Y of FIG. 2. As shown in the FIG. 4, a cavity is formed to thebottom side of the case 10 of the relay module 1 and a coil 102 as acomponent of the electromagnetic contactor is removed therefrom. Morespecifically, the relay module 1 is arranged such that the internalcomponents of the electromagnetic contactor are removed and the case 10and the terminals 1a through 1j are included therein, as describedabove.

Next, an arrangement of the relay module 1 when it is mounted on adistribution panel will be described.

FIG. 5 is a diagram showing the arrangement of the relay module when itis mounted on a distribution panel 20. As shown in the FIG. 5, the relaymodule 1 is used in the state that it is mounted on the distributionpanel 20. Here, the distribution panel 20 is connected to, for example,an I/O circuit of the programmable machine controller (PMC) of anumerically controlled machine tool and previously provided with aterminal base 22. As many relay modules 1, 11, 12 and the like asnecessary are continuously disposed on the left side of the terminalbase 22 in the figure. More specifically, the terminals 1f, 1g, 1h ofthe relay module 1 are connected to the terminals 22a, 22b, 22c of theterminal base 22 and the respective terminals of the other relay modules11 and the like are connected to the respective terminals of theterminal base 22 corresponding thereto.

Note, the distribution panel 20 has rails not shown disposed to theposition corresponding to the relay module 1 and the like and the relaymodule 1 and the like are disposed along the terminal base 22 by beingsimply engaged with the rails.

When the induction motor 30 is to be optionally connected to thedistribution panel 20 having the relay module 1 and the like disposedthereto, the electromagnetic switch must be provided for thedistribution panel 20. In this case, however, it suffices only toreplace the relay module 1 with the electromagnetic switch. Since therelay module 1 is previously provided with a wiring needed by theelectromagnetic switch, even if it is replaced with the electromagneticswitch, no wiring job is additionally required and only a terminalconnection job is necessary. Consequently, a time required to connectthe induction motor 30 is omitted. Thus a working time can be greatlyreduced as well as reducing cost.

The aforesaid can be similarly applied to the case in which theinduction motor 30 already mounted on the distribution panel 20 is to beremoved therefrom due to the change of a specification and the like. Inthis case, it suffices only to replace the electromagnetic switch withthe relay module 1 and no wiring job is not additionally required andonly a terminal connection job is necessary in the same way.

Further, since the relay modules 1, 11 and the like are mounted when theinduction motor 30 is not mounted, they may be used in place of aprimary terminal base which is conventionally mounted in parallel withthe terminal base 22. More specifically, the conventionally requiredprimary terminal base is not necessary and the space of the distributionpanel 20 can effectively used accordingly.

As described above, according to the present invention, the relay modulefor relaying the wiring of a motor circuit is composed of only the caseand terminal screws of the electromagnetic contactor for a motor fromwhich the internal components are removed. The relay module is disposedwhen the motor is not connected and the electromagnetic switch isdisposed when the motor is connected. Further, the relay module orelectromagnetic switch is wired at all times.

As a result, when a motor is optionally mounted on a machine tool, itsuffices only to replace the relay module with the electromagneticswitch and no wiring job is required. Further, when the motor is removedon the contrary, it suffices only to replace the electromagnetic switchwith the relay module and the wiring need not be removed. Therefore, atime required to connect the motor is omitted, thus a working time canbe greatly reduced as well as cost can be also reduced.

Further, a primary terminal base provided for a distribution panel isnot necessary and the space of the distribution panel can effectively beused accordingly.

We claim:
 1. A connection device for a numerically controlled machinetool, comprising:a distribution panel of said numerically controlledmachine tool; an induction motor; a relay module, including only a caseand a plurality of terminal screws for an electromagnetic contactor forsaid induction motor, mounted on said distribution panel; and anelectromagnetic switch which replaces said relay module to connect saidinduction motor to said distribution panel and to control a power supplyto said induction motor.
 2. A connection device according to claim 1,wherein contactors and electromagnetic driving contactors are removedfrom said electromagnetic contactor.
 3. A connecting method for anumerically controlled machine tool, comprising the steps of:providing arelay module including only a case and a plurality of terminal screws ofan electromagnetic contactor; mounting said relay module on adistribution panel of said numerically controlled machine tool; andreplacing said relay module with an electromagnetic switch to connectsaid distribution panel to an induction motor and to control a powersupply to said induction motor.
 4. A disconnecting method for anumerically controlled machine tool, comprising the steps of:connectingan electromagnetic switch to an induction motor and a distribution panelof said numerically controlled machine tool; providing a relay moduleincluding only a case and a plurality of terminal screws of anelectromagnetic contactor for said induction motor; and replacing saidelectromagnetic switch with said relay module to disconnect saidinduction motor from said distribution panel and to mount said relaymodule to said distribution panel.